The automatic transmission has been making little barely audible clunking sounds at times lately. I'm not sure if it's normal or if something is starting to go wrong.
I haven't changed the transmission oil in about 16 months, but we don't drive that many miles a year, maybe 11,000?
Is there a filter of any kind in the transmission that might be getting clogged from not changing the oil, and may be causing that little clunking sound at times?
Could be. 16 months is a long time, although 11,000 miles isn't far. Can you do this yourself, or know someone that can? It's easy, and not very expensive if you spin your own wrench. I would NOT recommend a flush unless the trans has been serviced regularly over the course of it's life, and even then, I shy away.
Clunking sounds rarely go away by themselves and tend to get worse over time. Toyota automatic transmissions rarely make clunking sounds so I suspect that the source of the sounds is not the transmission.
There is a screen in the automatic transmission, but unless the transmission is badly abused and on its last legs, I've never seen it get clogged. Automatic transmission fluid should be changed in accordance with the maintenance schedule in your owner's manual. If it has been over 60,000 miles since the fluid has been changed, then do not get it flushed - just drain and re-fill the fluid.
Lots of things can cause clunking sounds. If the brake pads are aftermarket, they sometimes clunk when changing direction from forward to reverse and vice versa. Other potential sources of clunking sounds are constant velocity (CV) joints, wheel bearings, struts and strut mountings, and loose and worn steering and suspension parts like ball joints and rack ends.
I have a hard time getting under there and don't have a rack or anything.
How come?
It's been serviced regularly, as far as transmission oil changes anyway.
This is the slightest little sound when accelerating and it shifts gears sometimes. Like if you step on the gas and it's changing gears, and you back off the gas because of traffic? It may even be normal and I'm just noticing it now, I dunno.
I've seen too many transmissions not work after flushing. If it has been serviced regularly, then the fluid should be in good shape. Drain and fill, and see what happens.
No competent technician will try to diagnose a sound without actually hearing the sound, unless the cause is a very common one. One person's "clunk" can be another's "click." Since clunking sounds are not common on Corollas, I would want to drive it and hear it before getting more specific than the possibilities I listed, and I would expect any competent technician to do the same. BTW, another possible cause is worn or broken engine mounts.
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